Semiconductor device structure and manufacturing method

ABSTRACT

A semiconductor device structure and a manufacturing method are provided. The semiconductor device structure includes a semiconductor substrate and a dielectric layer over the semiconductor substrate. The semiconductor device structure also includes a conductive trace over the dielectric layer. The semiconductor device structure further includes a conductive feature over the conductive trace, and a width of the conductive feature is substantially equal to or larger than a maximum width of the conductive trace. In addition, the semiconductor device structure includes a conductive bump over the conductive feature.

PRIORITY DATA

The present application is a continuation application of U.S. patent Ser. No. 14/208,948, filed Mar. 13, 2014 now U.S. Pat. No. 9,806,046, the entire disclosure of which is incorporated herein by reference.

BACKGROUND

Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment. The fabrication of the semiconductor devices involves sequentially depositing insulating or dielectric layers, conductive layers, and semiconductor layers over a semiconductor substrate, and patterning the various material layers using lithography and etching processes to form circuit components and elements on the semiconductor substrate.

The semiconductor industry continues to improve the integration density of various electronic components (e.g., transistors, diodes, resistors, capacitors, etc.) by continual reductions in minimum feature size, which allows more components to be integrated into a given area. The number of input and output (I/O) connections is significantly increased. Smaller package structures, that utilize less area or smaller heights, are developed to package the semiconductor devices.

New packaging technologies have been developed to improve the density and functions of semiconductor devices. These relatively new types of packaging technologies for semiconductor devices face manufacturing challenges.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIGS. 1A-1D are cross-sectional views of various stages of a process for forming a semiconductor device structure, in accordance with some embodiments.

FIGS. 2A-2C are top views of various stages of a process for forming a semiconductor device structure, in accordance with some embodiments.

FIGS. 3A-3B are cross-sectional views of various stages of a process for forming a semiconductor device structure, in accordance with some embodiments.

FIGS. 4A-4B are cross-sectional views of various stages of a process for forming a semiconductor device structure, in accordance with some embodiments.

FIGS. 5A and 5B are top views of semiconductor device structures, in accordance with some embodiments.

FIG. 6 is a top view of a semiconductor device structure, in accordance with some embodiments.

FIGS. 7A and 7B are cross-sectional views of semiconductor device structures, in accordance with some embodiments.

FIGS. 8A and 8B are cross-sectional views of semiconductor device structures, in accordance with some embodiments.

FIGS. 9A and 9B are cross-sectional views of semiconductor device structures, in accordance with some embodiments.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, or examples, for implementing different features of the invention. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. Moreover, the performance of a first process before a second process in the description that follows may include embodiments in which the second process is performed immediately after the first process, and may also include embodiments in which additional processes may be performed between the first and second processes. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

FIGS. 1A-1D are cross-sectional views of various stages of a process for forming a semiconductor device structure, in accordance with some embodiments. FIGS. 2A-2C are top views of various stages of a process for forming a semiconductor device structure, in accordance with some embodiments. Referring to FIG. 1A, a dielectric layer 102 is formed over a semiconductor substrate 100, in accordance with some embodiments. In some embodiments, the semiconductor substrate 100 is a semiconductor wafer (such as a silicon wafer) or a portion of a semiconductor wafer. In some embodiments, the semiconductor substrate 100 includes an elementary semiconductor material including silicon or germanium in a single crystal, polycrystal, or amorphous structure. In some other embodiments, the semiconductor substrate 100 includes a compound semiconductor, such as silicon carbide, gallium arsenide, gallium phosphide, indium phosphide, indium arsenide, an alloy semiconductor, such as SiGe, GaAsP, AlInAs, AlGaAs, GalnAs, GaInP, GaInAsP, or a combination thereof. In some embodiments, the semiconductor substrate 100 includes multi-layer semiconductors, a semiconductor on insulator (SOI) (such as silicon on insulator or germanium on insulator), or a combination thereof.

As shown in FIG. 1A, various conductive features are formed in the dielectric layer 102, in accordance with some embodiments. In some embodiments, the conductive features include multiple horizontal interconnects, such as conductive lines 104 a and 104 b, and multiple vertical interconnects, such as conductive vias 105 a and 105 b. In some embodiments, the dielectric layer 102 is a stack of multiple dielectric layers. The conductive features formed in the dielectric layer 102 form conductive paths between device elements (not shown) formed in or on the semiconductor substrate 100 and conductive traces over the dielectric layer 102. In some embodiments, a device element (not shown) is electrically connected to a conductive trace 106 a over the dielectric layer 102 through the conductive line 104 a and the conductive via 105 a. The device element may be a doped region formed in or over the semiconductor substrate 100. Alternatively, the device element may be a gate electrode formed over or in the semiconductor substrate 100. More conductive lines and conductive vias (not shown) may be formed between the conductive lines 104 a and the device element to form the conductive path.

Similarly, a conductive trace 106 b is formed over the dielectric layer 102, as shown in FIG. 1A in accordance with some embodiments. The conductive trace 106 b is electrically connected to another device element (not shown) formed in or on the semiconductor substrate 100. Through the conductive features, including, for example, the conductive via 105 b and the conductive line 104 b, the electrical path between the device element and the conductive trace 106 b is established.

In some embodiments, the conductive traces 106 a and 106 b are also referred to as top metals. In some embodiments, the conductive traces 106 a and 106 b are made of AlCu, Al, Cu, other suitable material, or a combination thereof. In some embodiments, the conductive traces 106 a and 106 b are formed by patterning a conducting layer deposited over the dielectric layer 102. For example, the conductive layer is patterned using a photolithography process and an etching process to form the conductive traces.

In some embodiments, the dielectric layer 102 is made of silicon oxide, silicon nitride, silicon oxynitride, tetraethylorthosilicate (TEOS) oxide, phosphosilicate glass (PSG), borophosphosilicate glass (BPSG), fluorinated silica glass (FSG), carbon doped silicon oxide, amorphous fluorinated carbon, low-k dielectric material, other suitable materials, or a combination thereof. In some embodiments, the conductive features formed in the dielectric layer 102 are made of copper, aluminum, tungsten, titanium, nickel, gold, platinum, other suitable material, or a combination thereof. A number of deposition, photolithography, and etching processes may be performed to form the dielectric layer 102 and the conductive features therein.

As shown in FIG. 1A, there is no passivation layer, such as a silicon nitride layer or the like, formed on the conductive traces 106 a and 106 b, in accordance with some embodiments. Therefore, fabrication cost and fabrication time are reduced. Embodiments of the disclosure are not limited thereto. In some other embodiments, a passivation layer (not shown) is formed over the dielectric layer 102 and the conductive traces 106 a and 106 b to partially cover the conductive traces 106 a and 106 b.

Referring to FIG. 2A, a top view of conductive traces 106 a and 106 b over the dielectric layer 102 is shown, in accordance with some embodiments. In some embodiments, the conductive traces 106 a and 106 b are conductive lines or conductive traces with uniform widths. In some embodiments, the conductive traces 106 a and 106 b include no wider (or protruded) region such as a circle region or an octangular region defined to serve as pad regions. Any region of the conductive traces 106 a and 106 b may be used as a pad region for forming a conductive bump thereon. No specific wider (or protruded) region is formed or defined to serve as the pad regions. In some embodiments, because no wider (or protruded) region is formed, the spacing between neighboring conductive traces is reduced. The density of the conductive traces is increased. More conductive paths connecting the device elements in the semiconductor substrate 100 may be established.

Afterwards, a conductive layer 108 is deposited over the dielectric layer 102 and the conductive traces 106 a and 106 b, as shown in FIG. 1B in accordance with some embodiments. In some embodiments, the conductive layer 108 is an under-bump metallization (UBM) layer. In some embodiments, the conductive layer 108 is a single layer or a stack of multiple layers. For example, the conductive layer 108 may be made of Ti, TiW, TiCu, Ni, other suitable material, or a combination thereof. In some embodiments, the conductive layer 108 includes sub-layers including, for example, a diffusion barrier layer and a seed layer. The diffusion barrier layer may be formed of tantalum nitride, although it may also be formed of other materials such as titanium nitride, tantalum, titanium, or the like. The seed layer may be a copper seed layer formed on the diffusion barrier layer. The copper seed layer may be formed of copper or one of many copper alloys that include silver, chromium, nickel, tin, gold, or a combination thereof. In some embodiments, the conductive layer 108 is deposited by using a PVD process, a CVD process, an electroplating process, a spin-on process, other applicable process, or a combination thereof.

Afterwards, the conductive layer 108 is patterned to form conductive features over the conductive traces, as shown in FIG. 1C and/or FIG. 2B in accordance with some embodiments. For example, photolithography and etching processes are performed to pattern the conductive layer 108 into the conductive features including conductive features 108 a and 108 b. As shown in FIG. 1C and/or FIG. 2B, the conductive features 108 a and 108 b are formed over the conductive traces 106 a and 106 b, respectively. In some embodiments, the conductive features 108 a and 108 b are under-bump metallization (UBM) elements.

In some embodiments, the conductive feature 108 a extends beyond the conductive trace 106 a. In some embodiments, the conductive feature 108 a extends over a sidewall 107 of the conductive trace 106 a, as shown in FIG. 1C and/or FIG. 2B. In some embodiments, the conductive feature 106 a further extends over the dielectric layer 102. Similarly, the conductive feature 108 b extends over a sidewall of the conductive trace 106 b, as shown in FIG. 2B in accordance with some embodiments.

In some embodiments, the conductive features 108 a and 108 b are wider than the conductive traces 106 a and 106 b thereunder, respectively. As shown in FIG. 1C and/or FIG. 2B, the conductive feature 108 a has a width W₂ which is larger than a width W₁ of the conductive trace 106 a, in accordance with some embodiments. In some embodiments, the width W₁ is a maximum width of the conductive trace 106 a. The width W₁ may be in a range from about 1 μm to about 40 μm. Alternatively, the width W₁ may be in a range from about 5 μm to about 30 μm. The width W₂ is larger than the width W₁ and may be in a range from about 15 μm to about 50 μm. As shown in FIGS. 2A and 2B, the conductive trace 106 a has various portions. For example, the conductive trace 106 a has a portion 202 b covered by the conductive feature 108 a and a portion 202 a not covered by the conductive feature 108 a. In some embodiments, the widths of the portions 202 a and 202 b of the conductive trace 106 a are substantially the same. The conductive feature 108 a is not formed over a specific wider (or protruded) portion of the conductive trace 106 a.

As shown in FIG. 1D and/or FIG. 2C, conductive bumps 110 a and 110 b are respectively formed over the conductive features 108 a and 108 b, in accordance with some embodiments. In some embodiments, the conductive bumps 110 a and 110 b are made of a solder material. The solder material may contain lead or may be lead free. In some embodiments, the conductive bumps 110 a and 110 b are formed by using direct placement, evaporation, electroplating, printing, jetting, stud bumping, other applicable methods, or a combination thereof. In some other embodiments, the conductive bumps 108 a and 108 b are made of other suitable conductive materials, such as copper. In some embodiments, the conductive bumps 110 a and 110 b are wider than the conductive traces 106 a and 106 b, respectively. In some embodiments, the conductive bumps 110 a and 110 b are made of other suitable conductive material. In some embodiments, the conductive features 108 a and 108 b are not formed. The conductive bumps 110 a and 110 b are formed directly on the conductive traces 106 a and 106 b, respectively.

As mentioned above, the conductive trace includes no wider portion (or protruded) region to serve as a pad region. The spacing between neighboring conductive traces is reduced. The density of the conductive traces is increased. Accordingly, the density of the conductive bumps is also increased. Pitches between the conductive bumps are significantly reduced in some embodiments. In some embodiments, no copper pillar or copper post is formed between the conductive bump 110 a and the conductive feature 108 a. Therefore, fabrication cost and fabrication time are reduced. The thickness of the semiconductor device structure is also reduced. After a subsequent packaging process, a package structure having a reduced thickness may be achieved.

In some embodiments, the structure shown in FIG. 1D is bonded to a substrate. FIGS. 3A-3B are cross-sectional views of various stages of a process for forming a semiconductor device structure, in accordance with some embodiments.

As shown in FIG. 3A, a substrate 300 is provided, which has conductive traces 302 a and 302 b formed thereon, in accordance with some embodiments. In some embodiments, the substrate 300 is an organic substrate. In some other embodiments, the substrate 300 is a multiple-layer circuit board. In some embodiments, the substrate 300 includes bismaleimide triazine (BT) resin, FR-4 (a composite material composed of woven fiberglass cloth with an epoxy resin binder that is flame resistant), ceramic, glass, plastic, tape, film, or other supporting materials. In some other embodiments, the substrate 300 is made of a semiconductor material. The substrate 300 may be made of a semiconductor wafer, or a portion of wafer. In some other embodiments, the substrate 300 is a printed circuit board. In some embodiments, the substrate 300 includes silicon, gallium arsenide, silicon on insulator (“SOI”) or other similar materials. In some embodiments, the substrate 300 also includes passive devices, such as resistors, capacitors, inductors and the like, or active devices, such as transistors. In some embodiments, the substrate 300 includes additional integrated circuits. The substrate 300 may further include through substrate vias (TSVs) and may be used as an interposer. In some embodiments, the conductive traces 302 a and 302 b are used to receive conductive terminals of another element, such as the structure shown in FIG. 1D. In some embodiments, the conductive traces 302 a and 302 b are made of copper, aluminum, gold, platinum, titanium, nickel, other suitable material, or a combination thereof. In some embodiments, a conductive layer is deposited and patterned to form the conductive traces 302 a and 302 b.

As shown in FIG. 3B, the structure shown in FIG. 1D is bonded with the substrate 300 to form a package structure, in accordance with some embodiments. In some embodiments, the conductive traces 302 a and 302 b are bonded with the conductive bumps 110 a and 110 b, respectively. In some embodiments, the conductive traces 302 a and 302 b are in direct contact with the conductive bumps 110 a and 110 b, respectively. In some embodiments, the conductive traces 302 a and 302 b and the conductive bumps 110 a and 110 b are bonded together using a thermal compression process, a thermal reflow process, other applicable processes, or a combination thereof. In some embodiments, a flux (not shown) or a solder paste (not shown) is used between the conductive traces 302 a and 302 b and the conductive bumps 110 a and 110 b to assist in the bonding process.

As shown in FIG. 3B, the conductive trace 302 a has a width W₃. The width W₃ and the width W₂ of the conductive feature 108 a may be defined along the same direction. In some embodiments, the width W₃ is in a range from about 15 μm to about 40 μm. In some embodiments, the difference between the widths W₂ and W₃ is not too much to ensure that no high stress is formed between the conductive traces and the conductive bumps during and/or after the bonding process. In some embodiments, a ratio of the width W₂ to the width W₃ (W₂/W₃) is in a range from about 0.5 to about 2.

In some embodiments, the conductive traces 106 a and 106 b, the conductive features 108 a and 108 b, the conductive bumps 110 a and 110 b, and the conductive traces 302 a and 302 b together form bonding structures between the semiconductor substrate 100 and the substrate 300. As shown in FIG. 3B, a protection material 304 is formed between the semiconductor substrate 100 and the substrate 300, in accordance with some embodiments. The protection material 304 may be used to protect the bonding structures between the semiconductor substrate 100 and the substrate 300. In some embodiments, the protection material 304 includes an underfill material, a non-conductive paste (NCP), other suitable insulating materials, or a combination thereof. In some embodiments, the protection material 304 is dispensed, flowed, and/or applied to surround the bonding structure of the package structure.

As shown in FIG. 3B, the protection material 304 surrounds the conductive traces 106 a and 106 b, the conductive features 108 a and 108 b, the conductive bumps 110 a and 110 b, and the conductive traces 302 a and 302 b. In some embodiments, the protection material 304 is in direct contact with the conductive traces 106 a and 106 b, the conductive features 108 a and 108 b, the conductive bumps 110 a and 110 b, and the conductive traces 302 a and 302 b. In some embodiments, the protection material 304 includes a resin material such as an epoxy resin, a phenol resin, other suitable material, or a combination thereof. In some embodiments, the protection material 304 further includes other additives, such as silicon oxide, carbon nanotube, other suitable additives, or a combination thereof. In some embodiments, the protection material 304 is dispensed, flowed, and/or applied between the semiconductor substrate 100 and the substrate 300. However, in some other embodiments, the protection material 304 is not formed.

Embodiments of the disclosure have many variations. For example, the conductive feature (such as the UBM element) is not limited to being wider than the conductive trace thereunder.

FIGS. 4A-4B are cross-sectional views of various stages of a process for forming a semiconductor device structure, in accordance with some embodiments. As shown in FIG. 4A, a conductive feature 408 a is formed over a structure similar to that shown in FIG. 1A, in accordance with some embodiments. In some embodiments, the conductive feature 408 a is a UBM element. In some embodiments, a sidewall 409 of the conductive feature 408 a is aligned with the sidewall 107 of the conductive trace 106 a, as shown in FIG. 4A. The conductive trace 106 a has a width W₄, and the conductive feature 408 a has a width W₅. In some embodiments, the widths W₄ is substantially equal to the width W₅. In some embodiments, the width W₄ is a maximum width of the conductive trace 106 a. The material and formation method of the conductive feature 408 a may be similar to those of the conductive feature 108 a shown in FIG. 1. A patterning process may be used to pattern a conductive layer (not shown) deposited over the conductive trace 106 a to form the conductive feature 408 a.

Afterwards, a conductive bump 410 a is formed over the conductive feature 408 a, as shown in FIG. 4A in accordance with some embodiments. The material and the formation method of the conductive bump 410 a may be similar to those of the conductive bump 110 a shown in FIG. 1D.

FIG. 5A is a top view of a semiconductor device structure, in accordance with some embodiments. In some embodiments, FIG. 5A is a top view of the structure shown in FIG. 4A. In some embodiments, the width of the conductive bump 410 a and the width W₄ of the conductive trace 106 a are substantially the same. In some embodiments, the width of the conductive bump 410 a is slightly wider than the width W₄ of the conductive trace 106 a. The conductive bump 410 a may substantially extend beyond the conductive trace 106 a.

As shown in FIG. 4B, a substrate 400 having a conductive trace 402 a formed thereon is provided, in accordance with some embodiments. In some embodiments, the material and formation method of the conductive trace 402 and the substrate 400 are similar to those of the conductive traces 302 a and 302 b and the substrate 300 shown in FIG. 3A.

Afterwards, the structure shown in FIG. 4A is bonded with the substrate 400, as shown in FIG. 4B in accordance with some embodiments. In some embodiments, the conductive trace 402 a is bonded with the conductive bump 410 a. The conductive traces 402 a may be in direct contact with the conductive bump 410 a. In some embodiments, the conductive trace 402 a and the conductive bump 410 a are bonded together using a thermal compression process, a thermal reflow process, other applicable process, or a combination thereof. In some embodiments, a flux (not shown) or a solder paste (not shown) is used between the conductive trace 402 a and the conductive bump 410 a to assist in the bonding process.

As shown in FIG. 4B, the conductive trace 402 a has a width W₆. The width W₆ and the width W₅ of the conductive feature 408 a may be defined along the same direction. In some embodiments, the width W₆ is in a range from about 15 μm to about 40 μm. In some embodiments, the difference between the widths W₅ and W₆ is not too much to ensure that no high stress is formed between the conductive traces and the conductive bumps during and/or after the bonding process. In some embodiments, a ratio of the width W₅ to the width W₆ (W₅/W₆) is in a range from about 0.5 to about 2.

As shown in FIG. 4B, a protection material 404 is formed between the semiconductor substrate 100 and the substrate 400, in accordance with some embodiments. As shown in FIG. 4B, the protection material 404 surrounds the conductive trace 106 a, the conductive feature 408 a, the conductive bump 410 a, and the conductive trace 402 a. In some embodiments, the protection material 404 is in direct contact with the conductive trace 106 a, the conductive feature 408 a, the conductive bump 410 a, and the conductive trace 402 a. In some embodiments, the materials and the formation methods of the protection material 404 are similar to those of the protection material 304 shown in FIG. 3B. However, in some other embodiments, the protection material 404 is not formed.

Embodiments of the disclosure have many variations. In some embodiments, more than one conductive feature (such as more than one UBM element) and/or more than one conductive bump are/is formed over a single conductive trace.

FIG. 5B is a top view of a semiconductor device structure, in accordance with some embodiments. As shown in FIG. 5B, two or more conductive features (such as UBM elements, not shown) are formed over the conductive trace 106 b, in accordance with some embodiments. In some embodiments, the width of each of the conductive features is substantially equal to the width of the conductive trace 106 b. In some other embodiments, the width of each of the conductive features is larger than the width of the conductive trace 106 b. The conductive features may define and/or determine the position and/or the profile of the conductive bumps thereon. In some embodiments, each of the widths of the conductive bumps 410 a and 410 b and the width of the conductive trace 106 b are also substantially the same. In some other embodiments, each of the widths of the conductive bumps 410 a and 410 b is slightly wider than the width of the conductive trace 106 b. The conductive bumps 410 a and 410 b may substantially extend beyond the conductive trace 106 b.

Embodiments of the disclosure have many variations. In some embodiments, a conductive feature (such as a UBM element) wider than a conductive trace thereunder and a conductive feature having a width substantially equal to that of a conductive trace thereunder coexist.

FIG. 6 is a top view of a semiconductor device structure, in accordance with some embodiments. As shown in FIG. 6, the conductive bump 410 a is formed over the conductive trace 106 a. In some embodiments, the width of the conductive bump 410 a is substantially equal to that of the conductive trace 106 a. In some embodiments, the width of the conductive feature (such as the UBM element, not shown) under the conductive bump 410 a is also substantially equal to that of the conductive trace 106 a, which is similar to that shown in FIG. 4A.

In some embodiments, two conductive bumps 610 a and 610 b are formed over the conductive trace 106 b, as shown in FIG. 6. In some embodiments, each of the conductive bumps 610 a and 610 b is wider than the conductive trace 106 b. In some embodiments, each of the conductive features (such as the UBM elements, not shown) under the conductive bumps 610 a and 610 b is also wider than the conductive trace 106 b, which is similar to that shown in FIG. 1D. In some other embodiments, two or more conductive features are formed over the same conductive trace, and some of the conductive features have different widths. For example, a first UBM element and a second UBM element are formed over the same conductive trace. In some embodiments, the first UBM element is wider than the conductive trace thereunder, and the second UBM element has a width substantially equal to that of the conductive trace thereunder.

Embodiments of the disclosure have many variations. FIGS. 7A and 7B are cross-sectional views of semiconductor device structures, in accordance with some embodiments. FIG. 7A shows a semiconductor device structure (or a package structure), in accordance with some embodiments. The semiconductor device structure is similar to that shown in FIG. 4B. The main difference is that a conductive bump 710 a is formed between the conductive traces 106 a and 402 a and covers the conductive trace 402 a. As shown in FIG. 7A, side surfaces of the conductive trace 402 a are covered by the conductive bump 710 a. In some embodiments, the materials and the formation methods of the conductive bump 710 a are similar to those of the conductive bump 410 a shown in FIG. 4B.

FIG. 7B shows a semiconductor device structure (or a package structure), in accordance with some embodiments. The semiconductor device structure is similar to that shown in FIG. 3B. The main difference is that a conductive bump 710 a′ is formed between the conductive traces 106 a and 302 a and covers the conductive trace 302 a. As shown in FIG. 7B, side surfaces of the conductive trace 302 a are covered by the conductive bump 710 a′. In some embodiments, the materials and the formation methods of the conductive bump 710 a′ are similar to those of the conductive bump 110 a shown in FIG. 3B.

Embodiments of the disclosure have many variations. For example, a conductive pillar may be formed between the conductive traces of two bonded substrates. In some embodiments, the conductive pillar is also used as a conductive bump or a portion of the conductive bump connecting the conductive traces.

FIGS. 8A and 8B are cross-sectional views of semiconductor device structures, in accordance with some embodiments. FIG. 8A shows a semiconductor device structure (or a package structure) similar to that shown in FIG. 4B. In some embodiments, a conductive pillar 812 is formed over the conductive feature 408 a, as shown in FIG. 8A. In some embodiments, the conductive pillar 812 is made of copper, aluminum, gold, platinum, titanium, nickel, other suitable materials, or a combination thereof. In some embodiments, the conductive pillar 812 is formed using an electroplating process, a PVD process, a CVD process, a spin-on process, other applicable processes, or a combination thereof. As shown in FIG. 8A, a solder bump 810 a is formed to bond the conductive pillar 812 and the conductive trace 402 a together, in accordance with some embodiments. The materials and the formation methods of the solder bump 810 a may be similar to those of the conductive bump 410 a shown in FIG. 4B. In some embodiments, the conductive pillar 812 and the solder bump 810 a are together used as a conductive bump between the semiconductor substrate 100 and the substrate 400.

FIG. 8B shows a semiconductor device structure (or a package structure) similar to that shown in FIG. 3B. In some embodiments, the conductive pillar 812 is formed over the conductive feature 108 a, as shown in FIG. 8B. In some embodiments, the materials and the formation methods of the conductive pillar 812 are similar to those of the conductive pillar 812 shown in FIG. 8A. As shown in FIG. 8B, the solder bump 810 a is formed to bond the conductive pillar 812 and the conductive trace 302 a together, in accordance with some embodiments. The materials and the formation methods of the solder bump 810 a may be similar to those of the conductive bump 410 a shown in FIG. 3B. In some embodiments, the conductive pillar 812 and the solder bump 810 a are together used as a conductive bump between the semiconductor substrate 100 and the substrate 400.

Embodiments of the disclosure have many variations. FIGS. 9A and 9B are cross-sectional views of semiconductor device structures, in accordance with some embodiments. FIG. 9A shows a semiconductor device structure (or a package structure), in accordance with some embodiments. The semiconductor device structure is similar to that shown in FIG. 8A. The main difference is that a conductive bump 810 a′ is formed between the conductive trace 402 a and the conductive pillar 812 and covers the conductive trace 402 a. As shown in FIG. 9A, side surfaces of the conductive trace 402 a are covered by the conductive bump 810 a′. In some embodiments, the materials and the formation methods of the conductive bump 810 a′ are similar to those of the conductive bump 410 a shown in FIG. 4B.

FIG. 9B shows a semiconductor device structure (or a package structure), in accordance with some embodiments. The semiconductor device structure is similar to that shown in FIG. 8B. The main difference is that the conductive bump 810 a′ is formed between the conductive trace 302 a and the conductive pillar 812 and covers the conductive trace 302 a. As shown in FIG. 9B, side surfaces of the conductive trace 302 a are covered by the conductive bump 810 a′. In some embodiments, the materials and the formation methods of the conductive bump 810 a′ are similar to those of the conductive bump 110 a shown in FIG. 3B.

Embodiments of the disclosure form conductive bumps and conductive features (such as UBM elements) over a conductive trace on a semiconductor substrate. The conductive trace has no wider (or protruded) region defined to serve as a pad region. The pitches between different conductive traces are significantly reduced since no specific pad region is defined. The layout area is not occupied by the wider (or protruded) region. Accordingly, the number of input and output (I/O) connections is significantly increased. A substrate is bonded with the semiconductor substrate to form a package structure through bonding a second conductive trace with the conductive bump. Fabrication cost and fabrication time are reduced, and the performance and the quality of the semiconductor device structure are improved.

In accordance with some embodiments, a semiconductor device structure is provided. The semiconductor device structure includes a semiconductor substrate and a dielectric layer over the semiconductor substrate. The semiconductor device structure also includes a conductive trace over the dielectric layer. The semiconductor device structure further includes a conductive feature over the conductive trace, and a width of the conductive feature is substantially equal to or larger than a maximum width of the conductive trace. In addition, the semiconductor device structure includes a conductive bump over the conductive feature.

In accordance with some embodiments, a semiconductor device structure is provided. The semiconductor device structure includes a semiconductor substrate and a dielectric layer over the semiconductor substrate. The semiconductor device structure also includes a conductive trace over the dielectric layer. The semiconductor device structure further includes a conductive feature over the conductive trace, and the conductive feature substantially extends beyond the conductive trace. In addition, the semiconductor device structure includes a conductive bump over the conductive feature.

In accordance with some embodiments, a method for forming a semiconductor device structure is provided. The method includes forming a dielectric layer over a semiconductor substrate and forming a dielectric layer over a semiconductor substrate. The method also includes forming a conductive feature over the conductive trace. A width of the conductive feature is substantially equal to or larger than a maximum width of the conductive trace. The method further includes forming a conductive bump over the conductive feature.

The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure. 

What is claimed is:
 1. A structure, comprising: a substrate; a conductive trace disposed over the substrate, the conductive trace including a first segment and a second segment that each extend in a first direction, wherein the first segment and the second segment have substantially equal dimensions measured in a second direction; a conductive layer disposed over the first segment, but not over the second segment, of the conductive trace, wherein a dimension of the conductive layer measured in the second direction is greater than the dimension of the first segment of the conductive trace; and a conductive bump disposed over the conductive layer.
 2. The structure of claim 1, wherein the conductive bump is in direct contact with the conductive layer.
 3. The structure of claim 2, wherein the conductive bump is separated from a sidewall of the conductive trace by the conductive layer.
 4. The structure of claim 1, wherein the conductive bump and the conductive layer have similar top view profiles.
 5. The structure of claim 4, wherein the conductive bump and the conductive layer each have rounded top view profiles.
 6. The structure of claim 1, wherein the conductive trace is free of having a passivation layer formed thereon.
 7. The structure of claim 1, wherein an entirety of the conductive trace has a uniform dimension measured in the second direction.
 8. The structure of claim 1, wherein the conductive layer is in direct contact with a sidewall of the first segment of the conductive trace.
 9. The structure of claim 1, further comprising: a further substrate having a further conductive trace formed thereon, wherein the further substrate is bonded to the substrate at least in part through the further conductive trace and the conductive bump.
 10. The structure of claim 9, wherein: the conductive bump is in direct contact with the further conductive trace; and the conductive bump has a greater dimension than the further conductive trace.
 11. The structure of claim 9, wherein the conductive bump is in direct contact with a sidewall of the further conductive trace.
 12. The structure of claim 9, further comprising a protection material disposed between the substrate and the further substrate, wherein the protection material surrounds the conductive bump.
 13. The structure of claim 9, further comprising: a conductive pillar disposed between the conductive bump and the conductive layer.
 14. The structure of claim 1, wherein a sidewall of the conductive trace is aligned with a sidewall of the conductive layer.
 15. The structure of claim 1, further comprising: a further conductive layer disposed over a third segment of the conductive trace; and a further conductive bump disposed over the further conductive layer.
 16. A structure, comprising: a first substrate; a first conductive trace disposed over the first substrate, the first conductive trace extending in a first direction including a first segment having a first width and a second segment having a second width, wherein the first width is substantially equal to the second width; an under-bump metallization (UBM) that wraps around a top surface and a side surface of the first segment of the first conductive trace; a conductive bump; a second substrate; and a second conductive trace; wherein the UBM and the second conductive trace are bonded to opposite sides of the conductive bump.
 17. The structure of claim 16, wherein: the conductive bump is in direct contact with the UBM; and the UBM prevents the conductive bump from coming into direct contact with the side surface of the first conductive trace.
 18. The structure of claim 16, wherein the conductive bump and the UBM each have a rounded top view footprint.
 19. The structure of claim 16, further comprising: a second UBM disposed over a third segment of the first conductive trace; and a second conductive bump disposed over the second UBM.
 20. A method, comprising: forming a conductive trace over a substrate, wherein the conductive trace extends in a first direction and has a uniform width measured in a second direction perpendicular to the first direction; depositing a conductive layer over the substrate and over the conductive trace, wherein the conductive layer and the conductive trace contain different conductive materials; patterning the conductive layer to form an under-bump metallization (UBM) that wraps around a first portion of the conductive trace, wherein the UBM is formed to be in direct contact with a side surface and a top surface of the first portion of the conductive trace; and forming a solder bump directly on the UBM, wherein the solder bump is formed using direct placement, evaporation, electroplating, printing, jetting, or stud bumping. 